“The one major positive was small caps were holding up this year, while big blue chips were cracking,” he says. “Now, seeing small-caps breaking down is a major concern going forward.”

But Friday’s drop puts the Russell 2000 just a hair above its 50-day moving average, a closely watched pivot point for short-term performance. The Russell hasn’t had a prolonged stretch meaningfully below its 50-day moving since the end of 2012.

Others cautioned not too read too much into Friday’s break lower for small caps.